Rockbox mail archiveSubject: Re: Cheap/good digital-audio Boston Acoustics BA735
Re: Cheap/good digital-audio Boston Acoustics BA735
From: Leslie Donaldson <donaldlf_at_lolth.aztechnologyinc.com>
Date: Fri, 5 Sep 2003 13:11:59 -0700
Well according to the page :
there is the wire version that feeds into a 75ohm cable (think networking
cables here) and a fiber version. The fiber version you could easily
make a splitter the cable version could be tough.
Also the S/PDIF IO is unidirectional..
from web site
Standard IEC958 "Digital audio interface" from EBU (European Broadcasting Union) details:
* Audio format : linear 16 bit default, up to 24 bit expandable
* Allowed sampling frequencies (Fs) of the audio:
o 44.1kHz from CD
o 48 kHz from DAT
o 32 kHz from DSR
* One way communication: from a transmitter to a receiver.
* Control information:
o V (validity) bit : indicates if audio sample is valid.
o U (user) bit : user free coding i.e. running time song, track number.
o C (channel status) bit : emphasis, sampling rate and copy permit.
o P (parity) bit : error detection bit to check for good reception.
* Coding format: biphase mark except the headers (preambles), for sync purposes.
* Bandwidth occupation : 100kHz up to 6Mhz (no DC!)
* Signal bitrate is 2.8Mhz (Fs=44.1kHz), 2Mhz (Fs=32kHz) and 3.1Mhz (Fs=48kHz).
* Cable: 75ohm +/-5% (l<10m) or 75ohm +/-35% (l>10m)
* Line driver:
o Zout: 75ohm +/-20% (100kHz .. 6Mhz)
o Vout: 0.4Vpp .. 0.6Vpp, <0.05Vdc (75ohm terminated)
* Line receiver:
o Zin: 75ohm +/-5%
o Vin: 0.2Vpp .. 0.6Vpp
Received on 2003-09-05